Vanilla/Turtle WoW support: M2 loading, bone parsing, textures, auth

- Vanilla M2 bone struct (108 bytes) with 28-byte animation tracks
- Version-aware bone parsing (vanilla vs WotLK format detection)
- Fix CharSections.dbc field layout for vanilla (variation/color at 4-5)
- Remove broken CharSections.csv files (all fields marked as strings)
- Expansion data reload on profile switch (DBC cache clear, layout reload)
- Vanilla packet encryption (VanillaCrypt XOR-based header crypt)
- Extended character preview geoset range (0-99) for vanilla models
- DBC cache clear support in AssetManager

include/pipeline/asset_manager.hpp

@@ -131,6 +131,11 @@ public:
      */
     void clearCache();
 
+    /**
+     * Clear only DBC cache (forces reload on next loadDBC call)
+     */
+    void clearDBCCache();
+
 private:
     bool initialized = false;
     std::string dataPath;